I considered this route. An iPad with 3G and data plan and jettisoning my iPhone. However, I rely too much on the iPhone-computer Contacts integration as well as other features. Sure I can live without Mail and apps like ScoreCenter on my Phone which leave a little too plugged in/connected. But I am really used to adding a contact to my phone and having it sync to my Mac and vice versa (added to which I have MobileMe so it does it without connecting). I also use the Google Maps app a lot, not for directions but really as a 411. Type in a name, let it find the location, tap it, tap the number and call. It is indispensable when we are out and about. So I will most likely pick up a WiFi only iPad at some point.